Pittsburgh studies innovation to “fix” its end of the Ohio River.

Every year, a single sewer spews 500 million gallons of mixed sewage and runoff into an Ohio River tributary. By the end of next year, nearly all of the sewage should be separated out of that flow, thanks to a $200 million environmentally friendly “green infrastructure” project that is part of a multibillion-dollar sewer improvement.

This project isn’t on Pittsburgh’s end of the Ohio, though. It’s in Cincinnati. Called the Lick Run Greenway project, it represents a model that environmental activists here would like to see adopted by Alcosan, which is starting its own multibillion-dollar sewer revamp.

Already, in the past two years, Alcosan has pledged $18 million to a host of environmentally friendly “green” upgrades designed to reduce the flow of runoff into the sewers, and it has hired an environmental engineering consultant, Dallas-based Jacobs Engineering Group. Environmental activists have praised those moves, while calling for a more ambitious approach.